title: The effects of catechin rich teas and caffeine on energy expenditure and fat oxidation: a meta-analysis.
abstract: Different outcomes of the effect of catechin-caffeine mixtures and caffeine-only supplementation on energy expenditure and fat oxidation have been reported in short-term studies. Therefore, a meta-analysis was conducted to elucidate whether catechin-caffeine mixtures and caffeine-only supplementation indeed increase thermogenesis and fat oxidation. First, English-language studies measuring daily energy expenditure and fat oxidation by means of respiration chambers after catechin-caffeine mixtures and caffeine-only supplementation were identified through PubMed. Six articles encompassing a total of 18 different conditions fitted the inclusion criteria. Second, results were aggregated using random/mixed-effects models and expressed in terms of the mean difference in 24 h energy expenditure and fat oxidation between the treatment and placebo conditions. Finally, the influence of moderators such as BMI and dosage on the results was examined as well. The catechin-caffeine mixtures and caffeine-only supplementation increased energy expenditure significantly over 24 h (428.0 kJ (4.7%); P < 0.001 and 429.1 kJ (4.8%); P < 0.001, respectively). However, 24 h fat oxidation was only increased by catechin-caffeine mixtures (12.2 g (16.0%); P < 0.02 and 9.5 g (12.4%); P = 0.11, respectively). A dose-response effect on 24 h energy expenditure and fat oxidation occurred with a mean increase of 0.53 kJ mg(-1) (P < 0.01) and 0.02 g mg(-1) (P < 0.05) for catechin-caffeine mixtures and 0.44 kJ mg(-1) (P < 0.001) and 0.01 g mg(-1) (P < 0.05) for caffeine-only. In conclusion, catechin-caffeine mixtures or a caffeine-only supplementation stimulates daily energy expenditure dose-dependently by 0.4-0.5 kJ mg(-1) administered. Compared with placebo, daily fat-oxidation was only significantly increased after catechin-caffeine mixtures ingestion.
authors.affiliation: Department of Human Biology, Nutrition and Toxicology Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands. rick.hursel@hb.unimaas.nl
authors.forename: R
authors.initials: R
authors.lastname: Hursel
authors.forename: W
authors.initials: W
authors.lastname: Viechtbauer
authors.forename: A G
authors.initials: AG
authors.lastname: Dulloo
authors.forename: A
authors.initials: A
authors.lastname: Tremblay
authors.forename: L
authors.initials: L
authors.lastname: Tappy
authors.forename: W
authors.initials: W
authors.lastname: Rumpler
authors.forename: M S
authors.initials: MS
authors.lastname: Westerterp-Plantenga
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D015992:Body Mass Index; D002110:Caffeine / Q000494:pharmacology*; D002392:Catechin / Q000494:pharmacology*; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004734:Energy Metabolism / Q000187:drug effects*; D006801:Humans; D010084:Oxidation-Reduction; D010936:Plant Extracts / Q000494:pharmacology*; D013662:Tea / Q000737:chemistry*; D022722:Thermogenesis / Q000187:drug effects
chemical_list: D010936:Plant Extracts; D013662:Tea; D002110:Caffeine; D002392:Catechin